I am relatively new to Heuers (only have a couple right now), but every day I'll learning more and more. Today, I had a question which is somewhat related to Heuers, and I was hoping someone on the forum can help me.

Who made the first watch with rotating bezel to measure time (unlike Harwood, which was used for winding)? A likely candidate is Heuer Flieger chronographs had the rotating markers was introduced in 1935 (notice the notch @ 23 minutes) - see picture below.

Doing some more research I came across this Unicorn in a Rolex case with a rotating bezel (notice the marker @ 55 min). As far as I know, Unicorns were produced from 1919 to 1933. Thus, due to production date and other features, like slightly older style lugs, the rotating bezel on this case seem to predate the Heuer. Notice an amazing similarity of the case construction between this watch and the Heuer, though the Heuer has later style more refined lugs and a larger marker.

Does anyone have any information on very early rotating bezel wrist watches? Especially anything predating this Unicorn

The Unicorn in question is about 40mm - not a small watch.

Thank you,

Vlad